Expansion joint dowel holder



R. R. ROBERTSON EXPANSION JOINT DOWEL HOYfJER June 11, 1946.

Filed April 29, 1944 v INVENTOR 2.23, Robertson ATTORNEYS Patented June 11, 1946 ENT OFFICE EXPANSION JOINT DOWEL HOLDER R'ussell R. Robertson, Patterson,

Calif., assignor,

by mesne assignments, of one-half to Elfreda C. Robertson, Patterson, Calif.

Application April 29, 1944, Serial No. 533,382 (o1. 94 51) '3Claims. 1 This invention relates to a device for holding or locating the dowels, such as used in connection with expansion joint strips, between adjacent slabs of concrete highways or runways, and which are employed to prevent relative vertical displacement of the concrete at said ends of the slabs. I It is necessary to maintain the dowels properly axially lined and parallel to each other and to the slabs if they are to properly perform their function and avoid cracking of the concrete with the expansion or contraction of the same. alinement must be done before the concrete .is poured and the dowels must be properly held in their alined position in such a manner that they will not be disturbed when the concrete is poured. At present this is done by placing a chairunder each dowel after the same is carefully placed in its proper position. 1 Frequently tie rods are used in addition to the chairs, and in all such operations not only is considerable time consumed, but the chairs and rods become permanently buried in the concrete, and since they cannot be reclaimed the amount of metal they represent is lost.

In View of this condition, it is the principal object of my invention to provide a dowel locating and retaining device by means of which all the dowels in a strip of reinforcing material may be simultaneously positioned and held in properly alined relation with each other in a, single, quickly performed operation.

A further object is to provide a device for the purpose which is adapted to be removed from its dowel locating position as soon as the concrete is poured, without danger of shifting the dowels from their set position and with a minimum disturbance of the concrete. The device is therefore capable of repeated use indefinitely and no metal is wasted. Also, the time needed to properly position and set the dowels is reduced to a minimum, and labor and time are conserved.

A further object of the invention is to produce a simple and inexpensive device, and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects I accomplish by means of such structure and relative arrangement of parts as will fully appear by a persual of the following specification and claims.

In the drawing similar characters of reference indicate corresponding parts in the several views:

Figure 1 is a fragmentary top plan view of my improved dowel locating and alining device.

Figure 2 is an enlarged cross section on line 2-2 of Fig. 1.

Figure 3 is a fragmentary elevation of the device adjacent one end thereof.

Referring now more particularly to the characters of reference on the drawing, the dowels I to be alined are mounted as usual ina strip 2 of suitable expansion material, which is set trans- [versely of the road or runway to be poured, and extends the full distance between the side limit boards or rails 3. The dowels extend through the strip in a common horizontal plane intermediate the top and bottom edges thereof in equally spaced relation throughout the length of the strip, and project substantially equal distances on opposite sides of the strip, as usual.

On one side of the strips the dowels are sheathed in thin sleeves 4 slidably fitted thereon. The sleeves preferably project some distance beyond the outer end of the dowels, as shown in Fig.

2, the projectingportions being filled by a compression or expansion plug 5.

My improved dowel locating and holding device to be used with the above described dowel arrangement and supporting strip comprises a saddle 6 of inverted U-shaped form adapted to removably but somewhat closely fit over the strip 2 nd to extend to the level of the bottom of the dowels or slightly below; the sidewalls 1 of the saddle being notched, as at B, to clear the dowels, as shown in Fig. 3.

Secured on each side wall 1 and projecting outwardly therefrom a distance less than the projecting portion of the dowels are rigid members 9 of substantially U-form in a horizontal plane and rigid with the saddle 6. These members are located above the different dowels and their outer end portions H), which are substantially parallel to the side walls 1, are centrally notched on their under sides, as at H, to form saddles fitting over the upper portion of the dowels. When the device is in place it is supported from the dowels by the notched portions ID, the top of the saddle 6 being then clear of the top of the strip 2, as shown in Fig. 2, so that the entire weight of the device rests on the dowels themselves.

The members 9 are preferably formed of sheet metal set on edge so as to offer a minimum area of resistance to upward movement through the concrete, and they may be formed as a continuous strip from end to end of the device, being then suitably bent to shape, as shown in Fig. 1.

The members 9 may be braced by diagonals l2 extending upwardly from their outer portions In to the saddle 6 adjacent the top, and said brace on one side of the saddle may be formed tress,

level of the bottom edge thereof the device may be provided with horizontal ears l6 orificed for the reception of locating stake if desired.

In operation, the saddle 6 is first placed over ,the strip 2, the device coming to rest on the dowels regardless of their initial alinernent. Said dowels are then tipped laterally as may be necessary to locate them in the notches II, and when the dowels are all so located they are in proper alinement both longitudinally and transversely of the road-bed. Also if necessary, and if the finger l4 are used, the dowels are shifted lengthwise to bring the corresponding ends against the fingers.

The weight of the device on the dowels holds them in such alined positions when the concrete is poured, so that such pouring will not disturb them. After 'the'p'ouring operation on opposite sides of the strip 2 is complete, the device is pulled str aightunthe thin area presented to the concretew-ith the upward movement of the device preventing any material disturbing-of the concrete'. Since the notches H are the only elements'aetually engaging "with the dowels at any tirn'elthe upward movement of the device away from the dowels 'does'not 'tend'to disturb or dislodge the same from their properfalined posiiFrom the foregoing description it -will be readrk s -f iais r su ed h de -i s substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims;

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

11s. device ,foruse in properly locating an expansion joint filler strip and dowels projecting *therethrough, whichdevice comprises a unitary structure including a saddle of substantially inverted U-shape tofit over the strip for substantially thelength thereof, relatively thin rigid U- shaped elements each having the free end of the 'legs thereof secured to a vertical side face of the saddle and such U-shaped element projectingthence horizontal-1y out from said side face of the saddle and the under edge of its closed outer end being provided with a notch adapted to fit over a dowel projecting through the -strip, whereby to hold the dowels at substantially right angles to the strip.

2-. A device as in claim 1, including 'a diagonal brace element interposed between and secured to the outer end of each of the U-shaped dowel locating members and the saddle.

3. A device as claim 1, including finger members of substantially equal length secured to and projecting from the outerends of the U- shaped dowel locatingmembers on one sideof the saddle,-such fingers being adapted to engage the ends ofthe dowels and limit the extent of their projection to that side of 'the saddle.

RUSSELL R. RGBERTSON. 

